The invention relates to a housing cover, particularly for the valve operating mechanism of an internal combustion engine, which includes, at one side thereof, a gasket structure molded thereon.
In many industrial areas, machines are used which employ oil or coolant in a surge-like fashion. In an internal combustion engine for example, the valve shafts are disposed in an oil spray. Because the oilsprayed or splurged around the rocker arms and valve shafts, it is necessary to seal the area including the oil or coolant against the ambient area. In order to make those areas accessible, they are generally provided with a removable cover. To prevent the escape of liquid, there is a gasket disposed between the housing and the housing cover. To facilitate assembly, the gasket is generally pre-mounted to the housing cover.
It is known to mold the gasket onto the housing cover. This is generally done by placing onto the side of the housing cover on which the gasket is to be disposed a tool which has cavities in the form of the gasket and injecting into these cavities a liquid seal material under high pressure. In order to retain the seal material in the cavities and prevent it from being squeezed out, the edges of the tool must be seated on the housing cover in a seal-tight manner. To achieve an appropriate seal the tool usually has, at the contact areas with the housing cover, wedge-like projections by which the housing cover is engaged and which, as a result, provide for a good seal structure.
The wedge-like projections do not only provide for the seal tightness, but they also accommodate manufacturing tolerances of the housing cover. Since it is not certain that the housing cover has always the same thickness in the area where the seal is to be applied, but the tool always comes down to the same working position the housing cover or the tool may be damaged if there is no tolerance adjustment. The wedge-like raised areas of the tool are therefore generally so dimensioned that they penetrate to a greater or smaller degree into the surface of the housing cover whereby they can accommodate relatively large manufacturing tolerances. To accommodate the manufacturing tolerances, the wedge-like projection however penetrate the housing cover to a much greater degree than it would be necessary to insure a proper seal. This has the disadvantage that unnecessarily large impressions are made into the housing cover
It is the object of the present invention to provide a housing cover with a seal structure in such a way that the impressions formed do not need to exceed the depth required for providing a good seal that is that they do not need to accommodate manufacturing tolerances.